Goals / Objectives Non-ruminant herbivores are not as efficient in the utilization of dietary fiberas are ruminants. However, they have developed several strategies that enable them to utilize diets containing high amounts of fiber. The objectives of this study are to further define strategies used by non-ruminants and to determine the effect of factors such as dietary manipulation, feeding management, processing of feedstuffs on the effectiveness of fiber utilization.

Project Methods A series of digestion studies will be conducted with horses, donkeys and non-ruminant exotic animals fed diets with various sources and level of fiber. The fiber source wil be presented in various particle sizes. The effect of frequency of feeding and level of intake will also be studied.

Progress 11/01/96 to 09/30/04

OutputsA series of digestion studies were conducted with ponies,light horses, draft horses, rabbits and guinea pigs. The results obtained from the three types of equids were similar. Moderate dental problems did not decrease rate of digestion in horses Rabbits digested the dry matter of timothy hay at lower efficiency than the other species.

ImpactsIncreased understanding of digestion in non-ruminant animals

Publications

No publications reported this period

Progress 01/01/03 to 12/31/03

OutputsThe Galapagos tortoise has a simple digestive tract with no compartment for extensive bacterial fermentation but it is a herbivore. It was hypothesized that the tortoise had a slow rate of passage, which may enhance digestion of plant material. A group of 5 Galapagos tortoises were fed one meal containing shelled corn. Feces were collected and the number of corn kernels present in the feces was counted. Kernels appeared in feces from day 3 to day 45. About 50 percent of the kernels collected appeared by 16 days and 90 percent appeared by 37 days. Digestion studies were conducted with two Galapagos tortoises fed alfalfa hay. The digestibility of dry matter, crude protein and neutral detergent fiber was 45, 70 and 22 percent respectively. An alfalfa hay of similar composition was fed to horses. The digestibility of dry matter, crude protein and neutral detergent fiber was 55, 74 and 40 percent respectively. Thus the tortoise was not as effective as the horse, a hind gut
fermenter. The data suggested that even though the rate of passage is relatively slow, neutral detergent fiber is not highly digested by the Galapagos tortoise.

ImpactsWill provide more understanding of the strategies used by non-ruminant herbivores to utilize fibrous feeds.

Publications

No publications reported this period

Progress 01/01/02 to 12/31/02

OutputsDigestion studies were conducted with four sheep, twelve rabbits and four guinea pigs fed timothy hay. No significant differences were found in apparent protein digestibility but the dry matter digestibility by rabbits was only 53 percent of that by sheep and the dry matter digestibility by guinea pigs was only 69 percent of that by sheep.

ImpactsThe data provides useful information that can be used to compare digestion coefficients obtained with different species of animals.

Publications

No publications reported this period

Progress 01/01/01 to 12/31/01

OutputsTwelve horses of light horse breeding (average body weight of 600 kg) and eight horses of draft breeding (average weight of 800 kg) were fed diets containing 85 percent grass hay (early or late hay). The remainder of the diet was oats. The early cut hay contained 12 percent crude protein and 60 percent NDF. The late cut hay contained 7 percent crude protein and 67 percent NDF. Digestion studies were conducted in December and repeated in February. There were no significant differences in apparent digestibility of nitrogen, NDF and dry matter between light and heavy horses. The early cut hay was significantly more digestible than the late cut hay.

ImpactsThe results indicate that digestibilities obtained in studies with light horses can be used in the evaluation of diets for draft horses and vice versa.

Publications

No publications reported this period

Progress 01/01/00 to 12/31/00

OutputsThe Battle of Little Bighorn was fought over 100 years ago but many controversies remain. Some feel the defeat of Custer could have been avoided if Benteen and Reno had united with Custer. A slow-moving pack train may have hindered the troops of Benteen and Reno from joining up with Custer. One report indicated the horses and mules in the pack train were lame and behaved crazily. It has been previously suggested that the animals had selenium toxicosis. It has been suggested selenium toxicosis does not cause locoism as previously thought. Plants in the Big Horn area contain both selenium and swainsonine. We propose the lameness could have been caused by selenium, but that the behavioral problems may have been caused by the ingestion of plants containing swainsonine.

ImpactsThe report may be of help to those interested in Battle of Little Big Horn and to reinforce to the horse owner the dangers of selenium and swainsonine toxicosis to horses.

OutputsThe effect of dental treatment on digestive efficiency was studied with 8 mature horses which had not had their teeth floated for at least 12 months prior to the start of the study. None of the horses had severe dental abnormalities. Digestion studies were conducted before and after floating of the teeth. Treatment did not significantly influence digestive efficiency. Twenty pregnant mares were fed diets containing early cut or late cut hay. The early cut hay contained 11% crude protein and 66% NDF compared to 7% protein and 68% NDF for the late cut hay. All mares were fed 2.3 kg of oats , a mineral supplement, and hay at a rate of 2% of body weight daily. Digestion studies were conducted during the sixth and ninth months of gestation: Stage of gestation did not influence digestibility. Apparent digestibility of protein was greater (p<.01) by mares fed the early hay (63.7% vs 51.7%). Nitrogen retention was greater by mares fed the early cut hay but all mares were in
positive nitrogen balance.

ImpactsThe data indicate that a lower concentration of protein than that recommended by the National Research Council can be fed to pregnant mares until at least the end of the 10th month of gestation without adverse effects in fetus or mare. A reduction in protein intake could reduce the amount of nitrogen release into the environment.

OutputsWater intake of donkeys (Equus asinus) having continuous or restricted access to water was compared. Three experiments were conducted at three temperatures (7, 15 and 20deg.C); each experiment was a 2-period cross-over with each animal receiving each treatment. Animals were adapted to the treatment for three days, and then intake was measured for five days. Following a three day adjustment period, animal switched treatment for the second period. Restricted access animals were offered filled buckets, left in the stalls for 15 min, then removed. Any buckets emptied in under 15 min were refilled. Water intake, expressed either as a percent of body weight or per kg of hay eaten, increased significantly (P<0.05) when animals had continuous access to water, regardless of environmental temperature. Because it evolved in a semi-arid environment, donkeys may be presumed to have a low water requirement and a tolerance for irregular access to water. Donkeys in our previous
studies have continued to eat despite water deprivation, and have shown an ability to replace water deficits incurred during forced deprivation. Donkeys in this study failed to adapt to, or compensate for, restricted drinking time. This suggests that, for some donkeys at least, food and water intake is likely to be maximized if water is provided more frequently than at 12 hour intervals, especially in warm environments.